1. Field of the Invention
The present invention relates in general to an input/output interface for an electronic computer system and more particularly to a device protection system for a multi-computer system interconnected through input/output interfaces of a bus type, which protection system serves for preventing the state or information of irrelevant devices from being destroyed due to possible erroneous operation of a central processor unit (CPU), thereby to enhance the reliability of the multi-computer system.
2. Description of the Prior Art
In a multi-computer system comprising a plurality of central processor units and input/output devices interconnected by means of interfaces of a bus line type, there has hithertofore been made no proposition as to the protection of the input/output devices as above mentioned. In general, which device is allowed to be used by a certain CPU in the multi-computer system is monitored or controlled through software technique. So far as the software as well as the employed hardware is operating in normal conditions, the protection of the devices will be unnecessary. However, there may arise the possibility of the state or information of irrelevant devices being destroyed due to overrun of the software or failure of the hardware in one of the central processor units or CPU particularly in the case of the multi-computer system having interconnections through the bus type interface, which may eventually involve the stoppage or shutdown of the whole system. Inherently, the multi-computer system has to be provided with means to prevent the shutdown of a certain CPU which may result in the shutdown of the whole system, since otherwise the reliability of the system will be lowered.